Related Experiment Video
Updated: Mar 8, 2026
14:53
Techniques for the Evolution of Robust Pentose-fermenting Yeast for Bioconversion of Lignocellulose to Ethanol
Published on: October 24, 2016
12.0K
Isomelezitose formation by glucansucrases
Gregory L Côté1, Christopher D Skory1
1Renewable Product Technology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, 1815 North University Street, Peoria, IL 61604, USA.
Carbohydrate Research
|January 23, 2017
Summary
Glucansucrase enzymes commonly produce isomelezitose, a trisaccharide. This study found that most tested glucansucrase strains can form isomelezitose from sucrose, indicating a general enzymatic reaction.
Area of Science:
- Carbohydrate Chemistry
- Enzymology
- Microbiology
Background:
- Glucansucrases are enzymes that synthesize glucans from sucrose.
- Isomelezitose is a trisaccharide with a specific structure: α-D-glucopyranosyl (1→6) β-D-fructofuranosyl (2↔1) α-D-glucopyranoside.
Purpose of the Study:
- To survey various glucansucrases for their ability to produce isomelezitose.
- To determine the prevalence and potential mechanisms of isomelezitose formation.
Main Methods:
- Screening of multiple glucansucrase-producing microbial strains.
- Quantification of isomelezitose yields relative to sucrose substrate.
Main Results:
- Nearly all tested glucansucrase strains produced isomelezitose, with yields ranging from <1% to approximately 5% of sucrose.
- Isomelezitose formation was observed to be a common outcome of glucansucrase activity.
Conclusions:
- Isomelezitose production is a widespread phenomenon catalyzed by glucansucrases.
- The formation of isomelezitose likely occurs through glucosyl transfer to either sucrose or isomaltulose intermediates.
Related Concept Videos
01:24Oligosaccharide Assembly
3.8K
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
Multiple sugar molecules that may or may...
3.8K
01:26Biosynthesis of Polysaccharides
822
Polysaccharides such as glycogen and starch are synthesized from nucleoside diphosphate sugars, primarily uridine diphosphate glucose (UDPG) and adenosine diphosphate glucose (ADPG). These activated glucose donors act as key intermediates in carbohydrate metabolism and biosynthesis. UDPG primarily involves glycogen synthesis in animals and many bacteria, while ADPG plays a fundamental role in starch synthesis in plants and certain bacteria.UDPG is formed when glucose-1-phosphate reacts with...
822
03:25Chemistry of Carbohydrates
92.3K
Carbohydrates are an essential part of the diet in humans and animals. Grains, fruits, and vegetables are natural sources of carbohydrates that provide energy to the body, particularly through glucose, a simple sugar that is a component of starch and an ingredient in many staple foods. The stoichiometric formula (CH2O)n, where n is the number of carbons in the molecule represents carbohydrates. In other words, the ratio of carbon to hydrogen to oxygen is 1:2:1 in carbohydrate molecules. This...
92.3K
00:57Carbohydrate Digestion
123.9K
Carbohydrate digestion and metabolism break down simple and complex carbohydrates from food into saccharides (i.e., sugars) for the body to use as energy. Carbohydrate digestion starts in the mouth during mastication, or chewing. The masticated carbohydrates remain intact in the stomach. Digestion resumes in the duodenum of the small intestine, where pancreatic alpha-amylase and brush border enzymes of the microvilli convert complex carbohydrates to monosaccharides. Finally, the monosaccharides...
123.9K
01:36Carbohydrate Metabolism
14.7K
Carbohydrates are polymers composed of molecules containing atoms of carbon, hydrogen and oxygen. One gram of carbohydrate can provide four kilo-calories of energy, which makes it the most efficient instant energy source.
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in...
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in...
14.7K
01:10Sugars as Energy Storage Molecules
10.1K
Sugar (a simple carbohydrate) metabolism (chemical reactions) is a classic example of the many cellular processes that use and produce energy. Living things consume sugar as a major energy source because sugar molecules have considerable energy stored within their bonds. Consumed carbohydrates have their origins in photosynthesizing organisms like plants. During photosynthesis, plants use the energy of sunlight to convert carbon dioxide gas into sugar molecules, like glucose. Because this...
10.1K